How do you beat a population which has all the capabilities of your population, EXCEPT they out-reproduce your population?
"Confine them in a finite space. Wait." You assume here that your population has advantages over the population you are combining. Your population has the power, the additional intellect, the grandfathered-in control of more resources, perhaps a persistent AND ENFORCED information advantage over the other population.
Without a significant asymmetry in your population's favor, when you combine them in a finite space, their population grows beyond yours, they now have the motivation and the ability to beat your population, to resolve whatever resource or information asymmetry in their favor that has previously allowed your population to dominate them.
We are not talking about humans vs cockroaches here. Or even if we are, the answer is the same. If humans became threatened by cockroach populations, we would (and do) simply kill them. We also come up with more clever ways of controlling their population, we introduce things into their environment which bring their population growth rate way down, even negative (i.e. we kill them?).
But transhumans A vs transhumans B, where A has decided to reproduce slowly? Unless B makes some correspondingly self-limiting decision, all other things being equal, population A will eventually dominate.
As I write this I do realize my claim that population A would need to be willing to kill defectors, to kill people who were obviously population B. I was also assuming an asymmetry: that population A would be willing to kill B and B not willing, or able, to kill A. The scenario I was thinking of was that the slow-reproducers at least for now have the population advantage and therefore the power advantage.
My underlying idea then would be that IF you propose a slow-growth policy for Transhumans, AND you wish to have this proposal survive for a long time, THEN you must PREVENT a significant population of transhumans who are just like you, EXCEPT they are fine with fast growth. You cannot allow a population which has the same fundamental capabilities as you do EXCEPT they have a higher population growth rate, to grow to a population size as big as yours, because if you do, you will soon pass a point where your own survival as a group is beyond your control.
If having the fast reproducers eventually "win," eventually dominate your group, is OK with you, then what is the point of the slow growth prescription in the first place?
If not having the fast reproduers eventually win is not OK with you, then what must you assume to even think that your population can produce an asymmetry which will cause the fast reproducers to either 1) stop reproducing even though they want to, and/or 2) die at a rate which counters their reproduction rate?
Either you crush them while you have some temporary advantage, or they eventually beat your population out. There is no third way, is there?
I might need a better title (It has now been updated), but here goes, anyway:
I've been considering this for a while now. Suppose we reach a point where we can live for centuries, maybe even millenia, then how do we balance? Even assuming we're as efficient as possible, there's a limit for how much resources we can have, meaning an artificial limit at the amount of people that could exist at any given moment even if we explore what we can of the galaxy and use any avaliable resource. There would have to be roughly the same rate of births and deaths in a stable population.
How would this be achieved? Somehow limiting lifespan, or children, assuming it's available to a majority? Or would this lead to a genespliced, technologically augmented and essentially immortal elite that the poor, unaugmented ones would have no chance of measuring up to? I'm sorry if this has already been considered, I'm very uneducated on the topic. If it has, could someone maybe link an analysis of the topic of lifespans and the like?